Britney Spears

Dancing like the world might end three times per week for four years — the last curtain closes on her Las Vegas residency December 31 — toned 5-foot-4 Spears into tip-top shape. The 36-year-old also puts in work offstage, lifting weights (overhead kettlebell lifts and biceps curls are two favorite moves), doing gymnastics and balancing it all out with twice-weekly yoga. On September 6, she showed off a handstand on Instagram, writing, “Life is actually better upside down.”

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Ciara

Fitness is a family affair for the 5-foot-7 Grammy winner. To get back to her goal weight after the April birth of her daughter (“I said I wasn’t going to gain 60lbs carrying Sienna, and . . . I did exactly that!!” she wrote on Instagram in June) the singer, 32, hit the gym with 3-year-old son Future and powered through training sessions with NFL quarterback husband Russell Wilson. One standout move: intervals with battle ropes.

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Gabrielle Union

The We’re Going to Need More Wine author is a big drinker. “I do a gallon of water a day,” she tells Us, noting she replaces high-sugar sips (think: Frappuccinos) with H20. “It’s helpful if you’re trying to lose weight.” As is eating veggies. The 5-foot-7 Being Mary Jane star, 45, aims for two daily servings of greens and works in yams and peppers to make her plate “as colorful as possible.” But balance is key, she stresses: “If you want the doughnut, have the doughnut.”

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Janet Jackson

Losing 70-plus pounds required control. Along with giving what London pro Paulette Sybliss called “100 percent” during weight- training sessions, the 5-foot-4 pop star, 51, stuck to a diet heavy in lentils, beans, quinoa and fish. “We wanted lean muscle,” Sybliss notes of the protein-packed plan. The result, she says of the mom to 11-month-old Eissa: “Her lower body responded awesomely and she’s very strong through the core.”

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Jennifer Lopez

The couple that sweats together stays together. And hot and heavy gym sessions are a major part of Lopez’s relationship with Alex Rodriguez. “Jennifer is an incredible athlete,” the 42-year-old former New York Yankee gushed to Us. “We work out together.” At home, the Shades of Blue star, 48, keeps her physique sleek by watching what she eats. “I have a lot of salad in the afternoon,” she tells Us. And to treat herself? “I really like cookies and cake, but something small, not huge.”

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Julianne Hough

Marrying a pro athlete did her body good. Asked to describe her ideal guy, “I was like, ‘I want somebody who is fit and loves to be active,” she tells Us. A healthy eater was a bonus. NHL forward Brooks Laich isn’t one to “trade a delicious meal for his health,” admits the 5-foot-3 star, 29, who plays fitness mogul Betty Weider in 2018’s Bigger. “So I had to kind of jump on board.” Whipping up tricolor cauliflower and other dishes has become fun, she says, “and I know what I’m putting in my body.”

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Karla Souza

This summer the star learned how to be a total badass. A regular in hip-hop classes and hot yoga, the How to Get Away With Murder actress, 32, tackled a triathlon with costars Jack Falahee and Conrad Ricamor. “I normally get bored running, I hadn’t swum for a while and I didn’t own a bike,” the 5-foot-4 ex-gymnast admits to Us. But she conquered her open water fears (“I think about the sharks!”) to finish the swim-bike-run combo. Says Souza, “I feel so much accomplishment.”

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Katharine McPhee

What the singer calls “next-level” workouts with trainer Simon Carter have left her 5-foot-8 physique ultratoned. “I’ve never built muscle like I’ve built with him,” the Scorpion star told Health in November of their cardio intervals. (Mid-run, she’ll stop to do 20 push-ups or jump squats.) The hard-core sessions have also strengthened her mind. In addition to therapy appointments, “an intense workout does so much for me mentally,” the 33-year-old admits. “It kinda goes hand in hand.”

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Kim Kardashian

The small things matter to the reality star. In an effort to tighten her 5-foot-3 shape after a 12-week hiatus from exercise last spring, the reality star began eating mini meals throughout the day. “She always keeps snacks on hand,” says an insider. “She does almonds and loves smoothies.” Coupled with 90-minute toning sessions alongside bodybuilder Melissa Alcantara, the strategy was a success. As the 37-year-old told Allure in September, “I’m, like, the most fit I’ve ever been.”

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Lady Gaga

As she battles chronic pain disorder fibromyalgia, the 5-foot-1 “Joanne” singer, 31, stays centered with yoga. The practice “makes me feel like I can do anything,” she has said. Fiber-packed foods also provide strength. On tour, her chef Bo O’Connor told Self, the six-time Grammy winner fills up on meals such as quinoa with black beans and shrimp. Says O’Connor, “Being able to provide your body with good nutrients, including those that are in vegetables and fruit, is everything.”

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Lauren Conrad

Mom life has helped the fashion mogul master fast and fresh meals. “Anything that’s quick is very appealing to me,” the 5-foot-4 Paper Crown designer, 31, tells Us. That usually means Rice Krispies with strawberries for breakfast (“I always want grains in the morning!”) followed by lots of protein. She and husband William Tell, parents of 6-month-old Liam, “do a lot of grilled chicken with vegetables. That’s a staple.”

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Lea Michele

Michele pulls double duty with her sweat sessions. “I look for workouts that are as good for my spirit as they are for my body,” the Mayor actress, 31, told Us at Gatorade and AwesomenessTV’s Sisters in Sweat summit. “I can’t be at the gym with crazy music playing and people looking at themselves in the mirror.” The 5-foot-3 star’s exercise of choice comes with a better view. Thanks to hiking trails near her L.A. home, “I can be on top of a mountain in 20 minutes.”

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Meghan Trainor

These days the singer is all about that healthy living. Three years after she bragged about loading up on pizza and Chinese food, the 24-year-old has committed herself to clean eating with the help of actor fiance Daryl Sabara. “We eat good and we work out, like, every day,” says the 5-foot-5 beauty, a judge on Fox’s new reality competition The Four: Battle for Stardom. As a result, she shared on Instagram in November, she’s “never felt so pretty/sexy in my life!”